Kerberos and Java Client to make requests to Cloudera Search

[#1]

Is the following link all that is needed for a Java Client to talk to Cloudera Search when protected by Kerberos?

http://www.cloudera.com/content/cloudera/en/documentation/cloudera-search/v1-latest/Cloudera-Search-...

Is it necessary to use Solrj to work with Kerberos, or can the Java client simply make http calls.

I am attempting without SolrJ, just using Java making http calls and it does not appear to work.  The Solr log states

6/17/2015, 10:37:19 PM

WARN

AuthenticationFilter

AuthenticationToken ignored: org.apache.hadoop.security.authentication.util.SignerException: Invalid signature

[#2]

Actually the error noted, does not appear to have anything to do with the Java client attempting to query Cloudera Search.  It appears some activity is happening about once a minute to cause this warning.

Still interested if anyone has tips regarding making a Java client work with Kerberos authentication to query a protected Cloudera Search.  I went ahead and code a simple Java app that does use Solrj (as the instructions in the link reference) and this did not work either.  Not sure if these instructions are incomplete, or I am missing something...